Evol Intent: The Rapture. The variation goes from slow and scary to a full-on sonic assault. Avoid Ninja Mono...
Surprisingly, the Ar tonelico II soundtrack ranges from insanely easy to insanely difficult. Particularly; Evil on the Moon (Which turned a corkscrew at one point) and Goddess' Footsteps, both of which are extremely fast and extremely bumpy rides.
Adding the tag [as-nogrey] to a song's title sounds like it would make Mono runs ridiculously easy, but it doesn't just remove the grey blocks. It replaces them all with colored blocks. And disables your ship's fins. Go try to collect every colored block on a fast song in Ninja Mono now. You can rack up insanely high scores this way, but your score will only be compared to those of other [as-nogrey] players.